Small-Scale Renewable Energy Systems A Review

By Paul Gipe

Small-Scale Renewable Energy Systems is a slim 210-page book on hybrid renewable projects by Swedish authors Sven Ruin and Göran Sidén.

Ruin is an engineering consultant with TEROC, the family firm. Sidén is a professor of Power Engineering at Halmstad University, Sweden and has developed the university’s renewable energy engineering program.

The university in Halmstad may not ring any bells on this side of the Atlantic but there has been increasing activity there with renewables in the past decade.

Halmstad’s on the windy west coast of Sweden across the Kattegat from Denmark midway between Gothenburg and Malmö. If you live in that part of the world you can’t escape the growth and success of wind energy.

However, with the exception of an exceptionally slow build out of commercial wind energy in the country, Sweden basically fell off the map of renewable energy development years ago despite the efforts of those like Sidén. He was part of a group that rescued a Vestas V27 from an early Swedish wind farm near Halmstad. Other turbines in the cluster were sold off to Ireland. Another in the group from the university to keep the turbine operating in Sweden was Erik Möllerström.

Möllerström, who teaches at the university, did his PhD research on a 200 kW straight-baded VAWT at Falkenberg north of Halmstad. This led Möllerström to summarize the past four decades of work with VAWTs in his peer-reviewed paper A historical review of vertical axis wind turbines rated 100 kW and above. (Disclosure: I am one of the coauthors of the paper.)

All of this is to say that North Americans shouldn’t discount the book because we haven’t heard of the authors or their university. There’s something going on there and it’s worth our while to pay attention to it. The university could turn out a new generation of engineering students schooled in renewable energy that could reinvigorate Sweden’s move to renewables.

I’ve worked with Ruin. He knows his stuff. When I was working in Toronto in the mid 2000s Ruin was the guy I’d call for questions on the performance of small wind turbines and how to test them. Since then he’s moved back to Sweden and continued his consulting practice.

The book’s section on wind is brief but thorough with all the essential formulas the field requires. The chapter also contains a rare table summarizing the test results of small wind turbines that have received certification. No doubt this table reflects Ruin’s interest in standard development from his participation in the IEA’s small wind task force.

Two sections in the chapter on case studies are worth the price of the book. One is on Samsø, the renewable energy island of the east coast of Denmark’s Jutland peninsular. The other is the much-hyped hybrid system on the island of El Hierro in Spain’s Canary Islands.

Samsø is a well known success story.

El Hierro was even more ambitious as it strove for a 100% renewable energy powered electricity system without access to a continental backup as in Samsø. It’s a pioneering project and not without its setbacks. Nevertheless, in 2018 the island produced 56% of its electricity with renewable energy. As explained in Small-Scale Renewable Energy Systems, the island has several options for expanding renewables contribution, especially now that solar has become so inexpensive.


Note: This is another book in a series that’s been sent my way to review or otherwise comment on. I no longer have the time or the inclination to read every book that’s sent over my figurative transom. These are all by highly valued colleagues or friends, the topics important, or the point of view well worth getting out to a broader audience. I am remiss in not getting to them in a timely manner. In lieu of just letting them gather dust, I am posting their bibliographic details and a comment or two.


Small-Scale Renewable Energy Systems: Independent Electricity for Community, Business and Home. Ruin, Sven and Sidén, Göran. Leiden, The Netherlands: CRC Press, 2019. 210 pages. ISBN-13: 9780367030971 (cloth). 6.9 x 0.7 x 9.7 inches. $100 USD. No country of origin stated.

Test Summary Report on Solid Wind 25 kW Turbine

Contents

1 Introduction

2 Electricity generation
2.1 Solar power
2.2 Wind power
2.3 Hydropower
2.4 Geothermal power
2.5 Bioenergy
2.6 Engine-driven generators
2.7 Wave power
2.8 Tidal power
2.9 Internet websites
2.10 References

3 Electricity storage
3.1 Battery basics
3.2 Lead-acid batteries
3.3 Nickel-based batteries
3.4 Lithium-based batteries
3.5 More than just a battery
3.6 Battery monitoring
3.7 Internet websites
3.8 References

4 Use of energy and electricity
4.1 Energy use in different sectors
4.2 Electrical power
4.3 How we use domestic electricity
4.4 Energy labeling and ecodesign
4.5 Examples of efficient use of energy in the commercial sector
4.6 Internet websites
4.7 References

5 System design
5.1 Basic considerations
5.2 Hybrid systems
5.3 Internet websites
5.4 References

6 Case studies
6.1 Hybrid system with direct methanol fuel cells
6.2 Self-sufficient home with pellet-driven CHP
6.3 House Unplugged
6.4 Home with seasonal storage of hydrogen
6.5 Farm with woodchip-driven CHP and solar PV
6.6 Municipal utility company using V2G and solar PV
6.7 Samso − a renewable energy island
6.8 El Hierro: self-sufficient island with pumped hydropower
6.9 Internet websites
6.10 References